Structure of DNA in spores of Bacillus cereus.

The structure of DNA extracted from dormant and germinating spores of B. cereus T was investigated using circular dichroism and other methods.No significant differences between DNAs extracted from vegetative cells and from spores of various stages could be found by analyses of CD spectra, CsCl density gradient centrifugation, melting profiles and template activity.All the DNA preparations were in B conformation and had the same density (1.695), Tm (83°C) and template activity in the reaction of DNA-dependent RNA polymerise.An abnormal DNA fraction of high density which was formerly found in B. cereus spores or a stable DNA complex with protein and/or RNA was not detected in the present extracts of spores.Preliminary X-ray analyses of intact spores indicate that the structure of DNA in spores is not so different from B form. when it is extracted and purified, and that no significant differences can be found between spore and vegetative cell DNAs.